In preparation for this talk I spent some time reviewing the past. What has happened in the last 50 years and why? I also asked myself the question: should a reasonably astute young man coming into the field at the end of World War II (as I did) have been able to predict what we see around us today? I believe he might have got some of it right but he would have missed a lot and the difference, I believe, is illuminating. Many of the fundamental questions are the same now as then. How old is the deep water? What controls species-species interaction? What are the processes that control energy and particle transfer at the ocean-atmosphere interface? How does one interpret the climatic and geological history of the earth from deep sea cores?